We　propose　a　new　picture　of　black　holes　through　a　special　holographic　screen.　This　holographic　screen　contains　all　the　degrees　of　freedom　of　a　black　hole.　We　find　that　this　holographic　screen　is　similar　to　the　ordinary　thermodynamic　surface　system.　Meanwhile,　through　the　＂white-wall　box＂　and　the　formula　of　sound　velocity,　we　find　some　similarities　between　gravitons　and　photons.　We　further　assume　that　such　a　holographic　screen　is　a　kind　of　Bose-Einstein　condensate　of　gravitons.　Through　this　assumption　and　those　similarities,　we　finally　get　the　area　law　of　static　black　holes.